Log debarking apparatus



Feb 24, 1948- w. F. DANIELL LOG DEBARKING PEARATUS4 y 5 sheets-sheet 1 Filed July 15, 1944- Feb. 24, 1948. w. F, DANlELL i `2,436,555 i I LOG DEBARKING APPARATUS Filed July 15, 1944 I5 Shgets-Sheet 2 VAR/asu PAM/EAA Feb. 24, 1948. w.`F. DANIELL LOG DEBARKING APPARATUS s--sheers-sheez s F11-ed July' V15.. 1944 fvvenor. VA' RRE/V 7T." DA MELA Patented-Feb. 24, 194s 2.436.555 h Loo nnnAnmNG APPARATUS Warren F. Danieli, Millinocket,

to Great Northern Paper Company,

Maine, assignor Millinocket,

Maine, a corporation of Maine Application July 15, 1944, Serial No. 545,177 4 Claims. (Cl. 14d-208) This invention relates to log debarking apparatus and has for an object the provision of an efllcient rapid apparatus for removing bark from logs.

inasmuch as the debarking is accomplished by striking the logs with a series of rapid, sharp. hammer blows, it is one object of the invention to minimize the noise, vibration, and wear appur tenant to usual impact debarking machines.y Further objects of the invention are the provision of control devices for insuring complete bark removal and for discharging the debarked 108 from the apparatus.

In its preferred form, the apparatus has a slotted deck or grid bed for supporting a log during the debarking operation and utilizes centriiugaliy acted upon hammers which pivot under centrifugal action into paths of rotation pro- :lecting through the grid to impart a succession of rapid blows against the bark of a log supported on the bed. The'bed has associated with it an arrangement for retaining the log in blow-receiving position and suitable mechanism designed to rotate the log relative to the bed and to move it, if necessary, longitudinally of the bed thus permitting the log to be subjected to blows at all surface points.

There is also associated with the apparatus a novel discharging mechanism for disposing of a log after the bark has been removed.

Details of the structure and operation of the apparatus will be better understood when described in connection with the accompanying drawinga'wherein:

Fig. 1 is a plan o1' the apparatus;

Fig. 2 is an end elevation thereof;

Fig. 3 is a cross-sectional view taken along the line 3-3 of Fig. 1;

Fig. 4 is a detail cross-section of the hammer carrying drum taken along the line 4-4 of Fig. 3, but broken away centrally;

Fig. 5 is an end elevation of the drum shown in Fig. 4 (omitting the hammers); and

Fig. 8 is an exploded view of certain of the parts making up the drum shown in Fig. 4.

The apparatus comprises a frame, the sides I Ii and I2 of which support a series of transverse, spaced bars or grids I4 forming collectively an inclined bed for supporting a log A to be debarked.

The bed is inclined to the left, as shown in Fig.

' 3, so that a log A supported on the bed will tend to roll under the influence of gravity to the left towards a series of log-turning rolls I5 mounted in longitudinally spaced relation on a shaft I6 imparted to the log by a series 2 lournalled in bearings I3, I3 carried by the frame.

As shown in Figs. 2 and 3, surfaces of the rolls I5 are desirabiy grooved in an axial direction so that they present a series of teeth I5a which will irictionally engage the log A as it is brought against the teeth i5a under the influence of gravity or otherwise.

The rolls I5 thus cooperate with the grids I4 of the log supporting bed to form a nip into which a log may be continuously urged. For the purpose of raising the point of contact between a log A and the rolls I5, the grids i4 are provided with upstanding inclined projections 20 (Figs. 3 and 4).

Debarking of the log is accomplished by blows of hammers 30 which are pivotally mounted, in a manner to be presently described, on a drum assembly 3| Y carried by a shaft 32 which extends longitudinally of the machine and is supported in bearings 34 rand 3B. The position ci the assembly 3l relative to the grids i4 and the position and proportion of the hammers 30 relative to the shaft 32 are such that during rotation of the shaft 32 the hammers 30 under centrifugal action pivot into paths of rotation projecting between the grids I4 of the log supporting bed, all as indicated in Fig. 3.

For the purpose of rotating the log turning rolls I5 in timed relation with the rotation of drum assembly 3i. the shaft I3, carrying rolls l5, is driven from shaft 32, driving drum 3|, by a belt running over shaft 32 at 42 and around pulley 4I carriedby shaft IB.

The log supporting bed is also provided at each end'thereof with mechanism for retaining a log the ebetween and for moving the log longitudinal y of the bed. This mechanism includes at the left hand side of the bed, as shown in Fig. l, a gate member hinged for swinging movement about a vertical plane on a rod 5I supported in a bracket 52 extending from frame I2. Afiixed to the member 50 is a rod 53 extending to the front of the machine and terminating in a handle 54 for operating the gate member 50 to move a log supported on the bed towards the right of the machine as shown in Fig. 1.

A similar gate member 55 is mounted at the other rear end of the machine for pivotal movement about a rod 56 similarly fixed in a bracket 51 exten-ding from the frame I2. However, the

gate member 55 extends below the shaft I6 and carries pivotally connected thereto at 51a a rod 58 extending to the front oi.' the apparatus and terminating in a handle 59. By proper manipulation of the control handles 54 and 58, a log may be moved in either direction for a short distance longitudinally of the bed. If desired, pivotal movement of gate members may be frictionally resisted to hold a. log in a predetermined position longitudinally of the bed.

The hammers 30 are assembled upon the drum 8| in the folowing manner, reference being had to the detailed showing of Figs. 4, 5, and 6, as well as to the cross-sectional View of Fig. 3. The shaft 32 carries a series of disks 83 longitudinally spaced along the shaft. Disks 60 are held in spaced relation by the interposition therebetween of annular metal spacers 6| keyed to the shaft 32 by a key 62. Each of the annular spacers 6| is of a relatively small diameter compared with the diameter of the disks 60 and is surrounded by a further annular disk-like spacing member 64 formed of shock absorbing material such as laminated fabric, solid rubber. or other resilient or semi-resilient material. The entire assembly is held in assembled relation by a series of bolts 85. shown as six in number, extending axial'y of the assembly and passing through flanged metal end plates 66 and 61, respectively. Nuts 68 on bolts 65 compress the entire assembly into an axially rigid structure, the key 62 being keyed into the end plates 66 and 81.

The hammers 30 are pivoted in every other space between disks 60 on a second set of axially extending pivot rods 18, also six in number in the form shown, radially spaced on the drum 3l outwardly of the members 64. As shown in Fig. 3, the hammers are shaped at their inner ends in such manner that they cooperate with the resi'ient shock absorbing members 64 to limit the arc of rotation of the hammers 38 about the pivots 10.

As indicated in the drawings, the spacing of the disks 60 and intervening hammers 30 on the drum 3l is so related to the spacing of the grids I 4 of the log supporting bed that the hammers, when extended from the drum, rotate in paths of rotation projecting through grids i4, so that each set of six hammers passes upwardly between two adjacent grids in each revolution of the shaft 32.

Thus, as shown in Fig. 3, the shaft 32, revolving in counter-clockwise direction. forces the hammers 30 under centrifugal action to be carried about the axis of shaft 32 in positions extending radiallv outwardly from the axis of the shaft as they rise to the right. further pivotal movement being prevented by contact of inner ends of the hammers with peripheral surfaces 68 of shock absorbers 64. Upon striking a blow against the log A, each hammer'rebounds from the log in such manner as to pivot clockwise around its pivot 10 until it bumps against a peripheral surface 68 of the resilient mateial 64 from which it rebounds or i-s'returned to extended position under the influence of centrifugal action prior to its return to impact position.

In order to further reduce the shook to the frame of the machine resulting from the blows imparted by the hammers 30, the pivots 10 pass loosely through the disks 60 and are mounted in resilient bearings 14 carried internally of annular spacers 12 (Fig. 4) positioned in spaces between disks 80 alternating with the hammers 38. As indicated in Fig. 5, the rods 1U may beheld relative to the end plates 68 and 61 by cotter pins 15.

In addition, the machine is provided with means for electing s. log A supported on tie bed after the debarking operation has been completed. For this purpose, at suitably spaced in tervals, grids I4 are omitted and are replaced by electing arms extending parallel with the grids I4. The arms 80 are fixed to a shaft 82 extending longitudinally of the frame beneath the bed, this shaft 82 being `iournalled in bearings 83 for oscillation relative to the frame i 2. At the forward end of the machine, there is connected to the shaft 82 a right angled lever arm 84 which acts as a handle for raising the arms 80 from an inoperative lowered position, as shown in Fig. 3, limited by stops 86 and 81 carried by the frame, upwardly through spaces between the grids i4 above the bed to raise a log supported on the bed therefrom and 'roll the log of! the bed and from the apparatus. V

The operation of the apparatus may be sume marized as follows:

A log A is positioned on the inclined bed of grids i4 where it rolls against log-turning rolls i 5. The shaft 32 is then revolved from a suitable power supply, rolls l5 simultaneously revolving in the same direction. Rotation of the shaft 32 revolves drum 3l, and hammers 30 thus successively rise between the grids and strike a. succession of sharp blows against the log A. Due to the location on the log of the points of impact, the log is continuously driven against the logturning rolls I5 which tend to turn the log in a clockwise direction, as shown in Fig. 3.

In an apparatus wherein the maximum radius of the path of rotation of the hammers 38 is about 18 inches, I have secured satisfactory debarking by rotating the shaft 32 at 125 R. P. M., shaft I6 rotating about 22 R. P. M. The disks 60 are spaced on 3%" centers to provide 1'? sets of hammers, each set comprising 6 hammers, making a total of 102 hammers. At the speed given. this, will provide 12,750 blows per minute to the bark.

lf debarking does not proceed satisfactorily, results may be hastened by adjusting the log longitudinally of the bed by movement of handles 54 or 59 which are designed to move the log a distance at least equal to the distance between sets of hammers 30.

When the log has been completely debarked the electing arm control 84 is lifted to raise the electing arms 80 to lift the log A oil the log sup- 1. Log debarking apparatus having a grid Y forming an inclined bed-for supporting a log to be debarked, a frictional log turning roll `mounted along the lower edge of said bed and forming with said bed a log receiving nip, a rotatable hammer-carrying drum mounted below said grid, means for rotating said roll in a direction such that the side of said roll adjacent said bed moves upwardly with respect to the bed, means for rotating said drum in the same direction, and debarking hammers pivotally mounted on said drum and adapted to pivot under centrifugal action during rotation of said drum into paths of rotation projecting through said grid to carry ends of said hammers against a log supported on ksaid bed and drive the log towards said log receiving nip.

2. In log debarking apparatus having a bed for` supporting a log to be debarked, a rotatable hammer-carrying drum assembly mounted adjacent said bed and comprising a rotatable shaft, a series of rigid disks spacedly mounted on said shaft, a plurality of radially spaced/rods extending axially of said shaft and passing loosely through said disks, a series of hammers pivoted on said rods between some of said disks for movement under centrifugal action during rotation of said assembly in radial planes into paths projecting beyond the periphery of said disks, and annular spacers mounted about said rods between other of said disks, and resilient bushings mounted internally of said annular spacers and around said rods for resiliently mounting said rods to absorb reaction shocks imparted to said assembly by said hammers in pounding a log supported on said bed during rotationv of said assembly.

3. In log debarking apparatus having a bed for supporting a log to be debarked and hammers spaced longitudinally of said bed for pounding a log supported on said bed, a gate member' pivotally mounted at each end of said bed for movement about an axis disposed at right angles to the longitudinal axis of said bed, said gate members being movable about said axes in a direction generally parallel tothe longitudinal axis of said bed for moving a log supported on said bed lon- I gitudinally thereof to expose the surface of the log throughout its longitudinal extent to the imf `pact of said hammers, f

4. In log debarking apparatus having a lbed for supporting a log to be debarked, a rotatable hammer carrying roll assembly mounted *adjacent said bed and comprising a rotatable shaft, a series oi disks mounted in spaced relation along said shaft. a plurality of rods spaced radially outwardly of said shaft and extending axially of said assembly through said disks. a series of hammers pivoted on said rods in spaces between said disks for movement under centrifugal action during rotation of said assembly in radial planes into paths projecting beyond the peripheries of,

said disks, to pound a log supported on said bed. and` resilient shock absorbing stops mounted about said shaft between said shaft and said rods and having surfaces defining the limits of pivotal movement in `both directions of each hammer and acting to absorb the shock of the reaction impact of said hammers on said roll assembly in pounding said log, said hammers having free pivotal movement throughout their paths of movement between said surfaces.

' WARREN F. DANIELL.

REFERENCES CITED UNITED STATES PATENTS Number Name Date 257,032 Loud Apr. 25, 1882 300,996 Merziger June 24, 1884 505,829 Hill Oct. 3, 1893 1,189,395 Shaw et al. July 4, 1916 1,300,748 Lambard Apr. 15, 1919 1,439,754 Plaisted Dec. 26, 1922 1,478,193 Ward Dec. 18, 1923 1,549,855 Cote Aug, 18, 1925 1,552,498 Noyes Sept. 8, 1925 1,670,723 Hummel May 22, 1928 1,873,697 Council Aug. 23, 1932 1,874,093 Fisher Aug. 30, 1932 1,905,387 Kirkwood Apr. 25. 1933 FOREIGN PATENTS Number Country Date 28,183 Germany Aug. 2. 1884 

